Battery vent plug



Feb. 19, 1963 R. c. SLAUTTERBACK 3,078,330

BATTERY VENT PLUG 3 Sheets-Sheet 1 Filed June 27, 1961 FIG. 3

FIG.J

FIG. 2

ROBERT C. SLAUTTERBACK FIG. 5

ATTORN YS Feb. 19, 1963 R. c. SLAUTTERBACK 3,073,330

BATTERY VENT PLUG Filed June 27, 1961 3 Sheets-Sheet 2 FIG; 8

92 I so ROBERT c. SLAUTTERBACR uvmvron.

ATTORN E S 1963 R. c. SLAUTTERBACK 3,078,330

BATTERY VENT PLUG 3 Sheets-Sheet 3 Filed June 27, 1961 FIG. 16

ROBERT C. SLAUTTERBACK INVENTQIIQ. A M/ ATTORNEYS nited Stats Fiied'lune 27, 1961, Ser. No. 119935 2 Ciaims. (Cl. 136-177) This invention relates to vent plugs for lead acid storage batteries and more particularly to vent plugs for storage batteries of the type used in automotive vehicles such as passenger automobiles and commercial vehicles.

It is well known to those experienced in the battery industry that a definite problem exists of satisfactorily venting wet storage battery cells to allow escape of generated gases, which are developed within the cell during normal charging periods, without allowing escape of the electrolyte liquid. In the past, it has been determined that a certain amount of electrolyte liquid escapes from the cell in the form of a mist or vapor, which is developed during certain charging periods when the electrolyte tends to boil. This mist or vapor escapes through the vent plugs along with the escaping gases. A certain amount of electrolyte liquid also escapes through the vent plugs as a result of splashing when the vehicle in which the battery is installed is subject to considerably rough use. it has also been determined that a certain amount of eiectrolyte will spill through vent holes in the vent plugs as a result of present day methods of transporting or storing vehicles in an angular position.

it is, therefore, a principal object of this invention to provide an improved lead acid storage battery vent plug of either the push-in type or the screw-in type which will have the necessary characteristics to prevent the loss of electrolyte liquid either by means of escaping vapors, splashing due to action of the vehicle in which the battery is installed, or spilling due to angular positions of the vehicle.

Another object of this invention is to provide a vent plug of the type described which will reduce to a minimum the amount of loss of electrolyte liquid, and still be more simple and economical to manufacture.

Another object of the invention is to provide a vent plug of the type described which is constructed of two pieces of plastic material in such a way that heating or cementing operations are not necessary to produce a completely assembled vent plug.

Still another object of the invention is to provide a push-in type battery vent plug constructed of two pieces of plastic material, one member being molded of a semirigid plastic and the other member being molded of a rigid plastic, so that, in the completed assembly, the rigid member tends to prevent deformation of the semi-rigid member when the vent plug is inserted in or removed from a battery cell opening.

Other objects and attendant advantages of the invention will become more readily apparent as the specification is considered in connection with the attached drawings in which;

FIG. 1 is a side elevational view of an assembled vent plug incorporating the features of this invention;

MG. 2 is a top plan view of the same vent plug;

FIG. 3 is a sectional elevation taken on line 33 of FIG. 2;

FIG. 4 is a composite view showing a sectional elevation of the two par-ts of the vent plug;

FIG. 5 is a top view, partly in section, of the main body of the vent plug;

FIG. 6 is a sectional elevation of a modification of the main body of the vent plug;

FIG. 7 is a sectional elevation of still another modification of the main body;

the two members are assembled.

, shown).

ice

FIG. 8 is a sectional view taken on line 8--8 of FIG. 6; FIG. 9 is a sectional elevation of another modification;

FIG. 10 is a sectional elevation taken on line 10-49 of FIG. 9;

FIG. 11 is a top plan view of the modification shown in FIG. 9;

FIG. 12 is a sectional elevation taken through another modification of an assembled vent plug;

FIG. 13 is a sectional elevation of the same body shown inFIG. 12 taken on a line transverse to the view shown inFIG. 12;

FIG. 14 is a top plan view taken on line 14 -14 of FIG. 13;

FIG. 15 is a sectional elevation of still another modification; and

FIG. 16 is a top plan view taken on line 1616 of FIG. 15.

Referring to the drawings, particularly FIGS. 1, 2 and 3, a two-piece molded plastic vent plug 10 is shown. The plug is a push-in type and comprises a main body portion or member 12 and a cap member 14. Both of the membets are molded of suitable acid-resistant plastic materials which will provide sufficient flexibility for the push-in portion of the vent plug and also provide a certain amount of rigidity to prevent deformation of the vent plug when inserted in or removed from a battery cell cover. It has been determined that a plastic material such as polypropylene or the like has the flexible characteristics desirable for thepush-in or main body member 12, and that a more rigid material such as polystyrene be used for the cap member 14 to reinforce the body member 12 when The main body 12 of the vent plug 10 is provided with a downwardly extending annular wall portion 16, the upper portion 18 of which has a conical configuration which terminates at its lower edge into a shorter inverted conical portion 20. The portion 20 of the annular wall 16 facilitates inserting the vent plug into a battery cell cover, and the entire annular wall, including the portions 18 and 20, will provide a liquid seal between the outer surface of the vent plug and the cell cover opening (not In some applications of the vent plug is may be desirable to provide additional flexibility of the wall portion 16 to facilitate inserting the plug into various other types of cell covers. This can be accomplished by providing one or more vertical slots 22 in the lower edge of the wall 16 which will allow a slight collapse of the Wall and reduce its outer circumference.

The conical portion 18 of the wall 16 terminates at its upper end into an annular horizontal flange portion 24-. A lower surface 26 of the flange 24 provides an abutment which cooperates with a portion of a battery cell cover (not shown) to determine the fully inserted position of the vent plug. Integral with the flange portion 24 is another annular wall 30 which extends upwardly and is provided with a plurality of vertical grooves or indentations 32 around its outer surface. The grooves or indentations 32 provide a finger-grip surface for easier manual installation or removal of the vent plug.

Around the inner surface of the wall 31), and near its upper edge, is a retaining groove 34, FIGS. 4 and 5. The groove 34 provides a means of retaining the cap member 14 in assembled position in the body member 12, which will be better understood hereinafter. A number of vertical slots 36 are provided in the upper edge of the wall 30 which provide a number of annular vent holes 33 around the upper portion of the vent plug when the cap member 14 is assembled in the body member 12.

Included in the body member 12 is an integral horizontal baflle 40 which has a dish-shaped configuration and is located midway between the top and bottom of the body annular wall 16. The battle 40 is provided with a central aperture 42., and an integral ring portion 44 extending downwardly from the bottom surface of the baffie 4d and surrounding the aperture 42. The aperture 42 is shown in the drawings as having a cross-shaped configuration which tends to prevent accumulated electrolyte from forming a film trap across the aperture. It is well known that a film of liquid will develop easily in a circular opening, whereas an opening formed of straight sides and/ or distinct corners tends to prevent the formation of such films.

The ring 4-4 is provided to prevent electrolyte that accumulates on the bottom surface of the baffie 4t), and due to dish-shaped configuration runs toward the aperture 42, from collecting around the edges of the aperture. Instead, the accumulated electrolyte will form droplets around a lower edge 46 of the ring and, due to vibration and gravity, fall from the vent plug back into the battery cell.

The cap member 14 (FIG. 4) comprises a horizontal disk-shaped portion 59, and a plurality of integral baffle tubes 52 extending downwardly from the bottom surface of the disk portion 50. The peripheral edge of the diskshaped portion 50 is provided with a taper, as shown at 54, which cooperates with the groove 34 in the main body .12 to retain the cap member 14 in an assembled position in the main body member. The process of assembling the two members consists of merely snapping the cap member 14 into position in the groove 34 of the body member. This type of construction eliminates the need for adhesives or heat-sealing operations commonly used in the past. When the cap member 14 is in position in the body 12 a relatively small area on the bottom surface of the disk-shaped portion 50 cooperates with a lower portion of the vertical slots 35 (FIG. 3) to form the annular vents 33'.

The downwardly projecting bafiie tubes 52 on the cap member 14 are provided for the purpose of causing a reversal or turbulence of escaping gases in a chamber 53 before they reach the vent holes 38. By providing a tortuous path within the vent plug chamber 533, the velocity of the gases will be reduced, allowing electrolyte vapors carried by the gases to gradually collect on the various inner surfaces of the vent plug rather than escape through the vents, resulting in a loss of electrolyte in the battery cell. As the vapors collect on the surfaces of the baffie portions 52 and the inner surface of the body member 12, they will gradually form droplets on the various edges and eventually return to the battery cell through the aperture 42.

The general relationship between the tubular baffles 52 and the structural configuration of the body member 12 prevents any splashing electrolyte from reaching the vents 38, and also reduces the volume of liquid allowed to spill from the battery cells if the battery is tilted.

The vent plug, as described hereinabove, is a preferred form of the invention, but the more desirable features of the invention may be incorporated in various other forms of vent plugs, as shown in FIGS. 6 through 6 inclusive.

In FIG. 6 a body member 6% is shown having a dishshaped bafile 62, a cap-retaining groove 64-, and a number of vertical slots 66 which will provide annular vent holes similar to the holes 38 in FIG. 3. The bafile 62 is provided with a cross-shaped aperture 68 identical to the aperture 42 in FIG. 5. The main differences between the body members 12 and 65) is that one is a screw-in type and that the battle 62 is located at the bottom of the body member 60.

In FIG. 7, a similar body member 79 is shown having a dish-shaped baffie 72, a cap-retaining groove '74, and a number of vertical slots 76. The baifie '72 is also provided with a cross-shaped aperture 78. In this form, the battle '72 is located midway between the top and bottom of the body member 70. Both of the forms shown in FIGS. 6

and 7 can be provided with a cap member having the same configuration as the cap member 14-, described hereinabove, and the same snap-in assembling feature.

Another modification is shown in FIGS. 9, 10 and 11. In these drawings, a push-in type body 30 is shown having a dish-shaped bafiie 82, a cap-retaining groove 84, and a number of vertical slots 86. The only difference between this vent plug body and the one in FIG. 4 is the aperture in the baffle 82. The aperture is formed by providing a rectangular opening $8 in the center of the baffie 82 with an integral curved hood 9!) directly over the opening 38. The hood appears to be a displaced portion of the baffie 82 as a result of forming the opening 88, but it is actually molded in position as an integral part of the baffle 82. The hood 90 is formed so that two openings 92 and 94 are provided, one on either side of the hood, between the lower longitudinal edges of the hood and the longitudinal edges of the rectangular opening 88. When the gases escape from the battery cell (not shown) through the opening 88, the hood will act as a bafiie and cause the gases to change direction. The gases will then travel at a reduced velocity through the openings 92 and .94, as shown by the arrows in the drawings. The body Bit can also be provided with a cap member similar to the cap 14 in FIG. 4.

In FIGS. 12, 13 and 14 another modification is shown wherein a screw-in type body 1% is provided with a conical baflle portion Hi2, and a similar cap-retaining groove 104. A cap member 106 is shown in the drawing which is provided with a downwardly-projecting baffie tube 1G8 and a vent opening 11%. The cap member 1% is assembled in the body 16% in the same snap-in fashion as the cap 14 and retained in position without adhesives or a heating operation. The conical bafiie m2 is an integral portion of the body member 10-9 and projects upwardly from the bottom edge of the body member 160. At the base of the conical baflle 102 are two oppositelydisposed openings 11% and 112, which are formed in much the same way as the aperture 8% in FIG, 9, that is, the openings 110 and 112 are substantially rectangular and provided with hood baffie portions 114 and 116 respectively. The hood baffles 114 and 116, resembling bridges between the body member 1G0 and a cone portion 118 of the bathe 1132, create side openings 120, 122, and 124, 126 respectively. As in FIG. 9, this arrangement causes escaping gases to change direction, thereby reducing the velocity of the gases before reaching an upper chamber 128 of the vent plug. Also, electrolyte film traps will not form in the vents due to the configurations of the various openings.

In the assembled plug, as shown in FIG. 12, the cone portion 118 projects a short distance into the lower end of the bafile tube 108 leaving an annular opening 130 between the lower edge of the tube and the annular surface of the cone portion 118. The annular opening 130 is located relatively low in the chamber 128, so that escaping gases will be required to change direction in the chamber 128, which again reduces the velocity of the gases before they reach the vent 110 in the cap 106. The tortuous path of the gas flow is shown by the arrows in the drawings.

Another modification, FIGS. 15 and 16, shows a vent plug body member 132 which is provided with a cap-retaining groove 134, and a conical baffle portion 136 having an upwardly projecting cone portion 138. This modification is similar to the one shown in FIG. 12, except for the vent openings in the bafiie portion of the main body. In this modification it has been determined that the velocity of the escaping gases is reduced by providing a plurality of radially disposed arcuate openings around the base of the cone 138. The gases can then be vented through a cap member similar to the cap member 196, or any modification thereof, which would be snapped into position in the groove 134.

It will be understood that the invention is not to be limited to the exact construction shown and described and that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. A two-piece molded plastic battery vent plug structure including a flexible main body member and a rigid cap member, the main body member having a downwardly projecting annular wall portion, an upwardly proecting annular wall portion, an intermediate horizontal flange portion integral with the upper and lower annular wall portions, an annular retaining groove in the inner surface and near the upper edge of the upper wall portion, an annular ridge positioned above said annular groove and having a diameter smaller than the diameter of said annular groove, said upper wall portion having a plurality of slots positioned in the peripheral edge and extending downwardly through said annular ridge and said annular groove, a substantially horizontal baflie formed integral with and positioned across the downwardly projecting annular Wall portion, said substantially horizontal bafile having an aperture positioned therein, said cap member having a disk-shaped portion, a tubular bafile projecting downwardly from said disk-shaped portion of the cap member over the aperture in said substantially horizontal bafile, said disk-shaped portion of said cap member having approximately the same diameter as said annular groove and having a slightly larger diameter than said annular ridge, whereby said disk-shaped portion of said cap member cooperates with the annular groove and the annular ridge in the main body member to provide a snap-in assembly arrangement of the two members, said slots in said upper wall portion providing sufiicient flexibility in the upper wall portion to permit said disk-shaped portion of the cap member to be snapped into said annular groove and providing a means for venting the plug.

2. A two-piece molded plastic battery vent plug structure including a flexible main body member and a rigid cap member, the main body member having a downwardly projecting annular wall portion, an upwardly projecting annular wall portion, an intermediate horizontal flange portion integral with the upper and lower annular Wall portions, an annular retaining groove in the inner surface and near the upper edge of the upper wall portion, an annular ridge positioned above said annular groove and having a diameter smaller than the diameter of said annular groove, said upper wall portion having a plurality of vertical slots in the peripheral edge projecting below a horizontal plane defined by the lowermost portion of the annular retaining groove, a dish-shaped horizontal baflie portion formed integral with and positioned across the main body member, said dish-shaped horizontal bafi'le having a central aperture positioned therein, said central aperture having a plurality of distinct corners and a plurality of substantially straight side walls, said cap member having a disk-shaped portion, a plurality of concentric baffle tubes projecting downwardly from the diskshaped portion; said disk-shaped portion of the cap memher having a diameter substantially equal to the diameter of said annular groove and slightly greater than the diam eter of said annular ridge, whereby said disk-shaped portion of said cap member cooperates with the annular groove and the annular ridge in the main body member to provide a snap-in assembly arrangement of the two members; said slots in said upper wall portion providing sufficient flexibility in said upper wall portion to permit said disk-shaped portion of said cap member to be snapped into said annular groove, and providing a means for venting said plug.

References Cited in the file of this patent UNITED STATES PATENTS Buskirk July 21, 1959 

1. A TWO-PIECE MOLDED PLASTIC BATTERY VENT PLUG STRUCTURE INCLUDING A FLEXIBLE MAIN BODY MEMBER AND A RIGID CAP MEMBER, THE MAIN BODY MEMBER HAVING A DOWNWARDLY PROJECTING ANNULAR WALL PORTION, AN UPWARDLY PROJECTING ANNULAR WALL PORTION, AN INTERMEDIATE HORIZONTAL FLANGE PORTION INTEGRAL WITH THE UPPER AND LOWER ANNULAR WALL PORTIONS, AN ANNULAR RETAINING GROOVE IN THE INNER SURFACE AND NEAR THE UPPER EDGE OF THE UPPER WALL PORTION, AN ANNULAR RIDGE POSITIONED ABOVE SAID ANNULAR GROOVE AND HAVING A DIAMETER SMALL THAN THE DIAMETER OF SAID ANNULAR GROOVE, SAID UPPER WALL PORTION HAVING A PLURALITY OF SLOTS POSITIONED IN THE PERIPHERAL EDGE AND EXTENDING DOWNWARDLY THROUGH SAID ANNULAR RIDGE AND SAID ANNULAR GROOVE, A SUBSTANTIALLY HORIZONTAL BAFFLE FORMED INTEGRAL WITH AND POSITIONED ACROSS THE DOWNWARDLY PROJECTING ANNULAR WALL PORTION, SAID SUBSTANTIALLY HORIZONTAL BAFFLE HAVING AN APERTURE POSITIONED THEREIN, SAID CAP MEMBER HAVING A DISK-SHAPED PORTION, A TUBULAR BAFFLE PROJECTING DOWNWARDLY FROM SAID DISK-SHAPED PORTION OF THE CAP MEMBER OVER THE APERTURE IN SAID SUBSTANTIALLY HORIZONTAL BAFFLE, SAID DISK-SHAPED PORTION OF SAID CAP MEMBER HAVING APPROXIMATELY THE SAME DIAMETER AS SAID ANNULAR GROOVE AND HAVING A SLIGHTLY LARGER DIAMETER THAN SAID ANNULAR RIDGE, WHEREBY SAID DISK-SHAPED PORTION OF SAID CAP MEMBER COOPERATES WITH THE ANNULAR GROOVE AND THE ANNULAR RIDGE IN THE MAIN BODY MEMBER TO PROVIDE A SNAP-IN ASSEMBLY ARRANGEMENT OF THE TWO MEMBERS, SAID SLOTS IN SAID UPPER WALL PORTION PROVIDING SUFFICIENT FLEXIBILITY IN THE UPPER WALL PORTION TO PERMIT SAID DISK-SHAPED PORTION OF THE CAP MEMBER TO BE SNAPPED INTO SAID ANNULAR GROOVE AND PROVIDING A MEANS FOR VENTING THE PLUG. 